Articles

To reach such a consistent theory which contains the quantum field theory of particle physics and Einstein’s theory of gravitation as limiting cases, one may proceed in the following way: Standard quantum field theory just ignores the effects of gravity. This is justified in many cases due to the weakness of gravitational interactions at the presently accessible scales. In a first step beyond this approximation, one may consider an external gravitational field that is not influenced by the quantum fields. Here one may think of sources of gravitational fields that are not influenced by the quantum fields under consideration, as high-energy experiments in the gravitational field of the earth or quantum fields in the gravitational field of dark matter and dark energy. This approach amounts to the treatment of quantum field theory on curved spacetimes. The problem of quantization in curved spacetimes is now clearly visible. In Minkowski spacetime, there is a large group of symmetries that enforces a particular choice of vacuum by demanding the vacuum to be invariant. Such a criterion is absent for a general spacetime (M,g). We therefore do not know which state to choose as the vacuum. One might hope that the different prescriptions might be unitarily equivalent such that it doesn’t matter which state one takes to define the theory. Sadly this is not the case: The Stone-Von Neumann theorem is no longer valid for systems with an infinite amount of degrees of freedom. This means that unitarily inequivalent representations of the canonical commutation relations will arise, and it is not clear which equivalence concept representation is the physical one. In the second section of this chapter, we review the notions of Cauchy surfaces and global hyperbolicity.

Background: Dysgerminomas, account for only 1% - 2% of all malignant ovarian neoplasms.Objective: This case report aims to present a rare occurrence of dysgerminoma in a pediatric patient, highlighting the clinical characteristics, diagnosis, and management.Case presentation: We present a case of dysgerminoma in a 12-year-old girl who presented with a three-week history of pelvic pain and progressive abdominal swelling. Physical examination revealed a distended abdomen with evident suprapubic fullness, and a palpable abdominopelvic mass measuring approximately 20 weeks in size. Imaging studies confirmed the presence of a solid heterogeneous mass originating from the pelvis. The patient underwent a right salpingo-oophorectomy without complications. Histological examination coupled with an immunohistochemical study confirmed the diagnosis of dysgerminoma. The patient had an uneventful postoperative course and was discharged without adjuvant treatment. Regular follow-up visits, physical examinations, ultrasound scans, and lactate dehydrogenase assays were initiated for monitoring. Conclusion: Prompt recognition and appropriate surgical intervention, followed by regular monitoring, are crucial for optimal outcomes in pediatric dysgerminoma cases.

Biochemical systems are analytically investigated after encoding the properties of the dynamics, which rule the time evolution of the transition properties, using some Markov models, such as the Hierarchical Markov-State Models. The present paper is aimed at analytically writing the (finite) Markov chain originating from the considered Markov models. Within this framework, the interaction with the environment is considered, and the ergodicity of the systems obtained from numerical simulation is controlled and compared with the qualities of the Markov chain. The (von Neumann) conditions to be imposed on the Bloch equations for the biomaterial structures to be described analytically in a consistent way are governed. The formalisms of the ’heat bath’ and that of the control of the numerical errors ensure the good measure-theoretical framework and the ergodicity of the finite chain, respectively.The finite Markov chains are investigated and the analytical expressions are presented, after which the Hierarchical Markov-State-Model provides the time evolution of the transition probabilities in biochemical systems.The notion of heat bath is used to describe the interactions of the biomaterial with the environment and thus to control the uses of the projection operators in the Markovian processes where the appropriate measure is defined; the stochastic equations allow one to obtain the wanted measure from the probability spaces.The cases in which a violation of the Markov property of the process occurs, i.e. in open systems, or dissipative processes are also considered. Furthermore, in complex molecules in biological systems, these features are investigated to be possibly even more dramatic. As far as molecular processes are concerned, this occurrence is associated with the appearance of chaotic effects with certain characteristics of potential surfaces: rather than the technique of isocommittors, the method of projectors in measure spaces is used for the Nakajima-Zwanzig paradigm for the density operator; this latter method complementary compares the time-convolution-less technique.The finite Markov chains are finally proven to be ergodic after the control of the numerical errors which provide the Sinai-Markov partitions to be applied for the analysis of the measure space of the Markov chain, that is, one endowed with a Hilbert measure. The von Neumann conditions are therefore newly demonstrated to be apt to be applied to the Bloch equations for biomaterial structures after the use of the notion of heat bath, from which the measure space arises.The qualities of the Hierarchical Markov-Sate Models which bring the analytical expression of the time evolution of probabilities of biomaterials are therefore newly analytically studied.

Computational models used in specifying biological systems represent a complement and become an alternative to more widely used mathematical models. Amongst some of the advantages brought by these computational models, one can mention their executable semantics and mechanistic way of describing biological system phenomena. This short overview report enumerated some of the computational models utilised so far in systems and synthetic biology, the associated analysis and formal verification methods and tools, and a way of facilitating a broader use of this alternative approach.

Two female patients in their fifties with a previous history of cutaneous malignant melanoma were found during follow-up to have a 'hot' lesion in the gallbladder on a Positron Emission Tomography scan. Imaging showed a gallbladder polyp. Histology revealed infiltration of the polyp mucosa by metastatic malignant melanoma. One case had a BRAF mutation. A male in his 70s was found on a staging computed tomography scan to have a suspicious intraluminal lesion in the gallbladder and thickening of the sigmoid colon. Subsequent histology confirmed metastatic malignant melanoma in the chest wall and to the gallbladder and adenocarcinoma in the colon. Molecular testing showed BRAF mutation. The metachronous adenocarcinoma in the colon was mismatch repair protein proficient and had no KRAS mutation. Histology from all cases showed that metastatic malignant melanoma to the gallbladder is superficial.Discussion: Reports from autopsy examinations revealed that metastasis from malignant melanoma to the gallbladder can be up to 15% - 20%. Most patients have mild symptoms or are asymptomatic which explains the paucity of cases reported in living patients within the published literature. Most of the previous reports showed the metastatic malignant melanoma to the gallbladder presented macroscopically as a polyploidal lesion. Conclusion: Our histological observation and previous reports showed that metastatic malignant melanoma in the gallbladder tends to be superficial. All our cases show no lymphatic or vascular invasion in the histological examination as previously published reports, however, the hematological spread is the most commonly suggested mechanism of spread.

Background: Temporomandibular Disorder (TMD) pain attributed to myalgia is a common condition and patients should get advice on the best treatment option. Objectives: The aim was to evaluate the effect of two different exercise programs, or bite splint therapy, respectively, in patients with chronic frequent primary myofascial orofacial pain. Methods: The study was a randomized clinical trial including patients fulfilling criteria of chronic frequent primary myofascial orofacial pain with a reported pain intensity of ≥ 4 on a numerical rating scale (0-10). Ninety subjects were randomized to either bite splint, home exercises, or a supervised exercise program. Two examiners blinded to the treatment modality examined the same subject at baseline and a 3-month follow-up. Non-parametric statistical methods were applied for the outcome of treatment in intended-to-treat analyses. A P-value <0.05 was considered statistically significant. Results: The pain severity index was significantly reduced (p < 0.001) in all treatment groups. Jaw opening capacity improved significantly (p < 0.05) for those randomized to bite splint and for those in the home exercise program. About 70% of the participants reported improvement in their TMD pain severity with no significant difference between treatments. Both exercise groups improved in jaw function at the 3-month follow-up compared to baseline. Those who had a bite splint reported significantly more improvement in their headaches compared to those in the exercise programs. Conclusion: Jaw exercise programs and bite splint treatments had similar positive effects on TMD pain severity attributed to myalgia after 3 months.

In a young patient with iron deficiency anemia and low hemoglobin levels, we identified a very rare association: Demyelinating disease with Inflammatory Bowel Disease (IBD).

Post-stroke vocal cord paralysis is a condition much less recognized compared to dysphagia. We describe bilateral vocal cord palsy in a thirty-six-year-old man following a stroke. 

Background: Early-onset sarcoidosis is a rare systemic inflammatory granulomatous disease, distinguished by onset before the age of 4 and notably lacking pulmonary involvement. Unfortunately, the condition often shows clinical features similar to juvenile idiopathic arthritis, resulting in the misdiagnosis of numerous patients. This case report delves into the challenges associated with the delayed diagnosis of early-onset sarcoidosis, with a particular focus on the diagnostic methods employed to address this delayed recognition.Case presentation: A 15-year-old girl presented with a history of recurrent fever since infancy, accompanied by rash, arthritis, and joint deformity. Previously misdiagnosed with juvenile idiopathic arthritis, she underwent management with steroids and methotrexate, yielding no improvement. The diagnosis of early-onset sarcoidosis was made during adolescence based on serial examinations, comprehensive laboratory and radiological evaluations, and subsequent histopathology findings. Presently, the patient is receiving treatment with low-dose steroids and biologic therapy (Tocilizumab) and experiencing no disease progression.Conclusion: This case report underscores the importance of considering early-onset sarcoidosis in the differential diagnosis of pediatric patients exhibiting persistent arthritis from an early age. Early detection and treatment are crucial in averting complications and enhancing the overall quality of life. 

Antibiotic resistance is a growing global crisis, straining healthcare systems and leaving us with limited options to combat drug-resistant bacteria. This retrospective, cross-sectional study examines the prevalence of antibiotic resistance patterns among urinary tract infections (UTIs) in Al-Shifa Hospital’s medical departments in comparison with non-medical departments using data from microbiology laboratory archives over a one-year period. From the examined urine cultures about 25% were obtained from internal medicine departments and double the number was obtained from non-medical departments. The positive rate was around 35% and about two-thirds of the samples were collected from female patients. Among all departments, Enterobacteriaceae spp. were found to be the most frequently isolated uropathogens, accounting for 80% of cases. However, resistance rates varied depending on the specific organism and antibiotic used. For instance, E. coli showed a resistance rate of only 5% against meropenem, while amoxicillin-clavulanic acid exhibited a resistance rate exceeding 95%.Importantly, the study revealed a significant disparity in resistance rates between medical and non-medical departments, specifically concerning third-generation cephalosporins. In internal medicine departments, resistance rates were alarmingly high, with cefotaxime, ceftriaxone, and ceftazidime showing resistance rates of 75%, 75% and 66.5% respectively. In contrast, non-medical departments displayed lower resistance rates, approximately 60%, 60% and 40%, respectively.In summary, this research sheds light on the escalating problem of antibiotic resistance in UTIs and emphasizes the discrepancy in resistance rates between medical and non-medical departments. Urgent efforts are required to address this issue and find effective solutions to prevent the rise of untreatable bacterial infections.